Art of producing step-by-step movements



F. W. WOOD.

ART 0F PRODUCING STEP-BY-STEP MOVEMENTS.

APPLICATION FILED Nov. I3. ISIS.

Patented Mar. 7, 1922.

A 33 z v jj I m L I Y, .30

l IIII IIIIIIIIIIIII I IIIIIIIIIIIIII.

3 nueva/tofu m/v/f 1404/0017 mbo/mam Mk1@ ML@ fk o UNITE i FRANK w. woon, or NEW Yoan, n'. Y.,.essicnoie 'ro errantes'. conv a soimnrnoonromi'riin, or New Yoan, n. Y., a conronaricn or new Yoan.

To all tlmay concern v l Be it known that l, "FRANK VV', Woon', a citizen of the United States,eresid1ng at New York, in the county of New York yand Y,

State of New York, have invented newvr and useful Improvements in the Art of Producing Step-by-Step Movements, of which -t-he following is avspeciication. s

This invention relates t improvements in the art of producing step-by-step movements to a rotatable element, pertaining more particularly to that type ot Suchin- `ventions wherein the element movements are provided ,by the resultant action of a plurality of magnetic circuits.

. For the4 p-urpose oi explaining the pres- 'ent invention, I have shown it as employed in connection with a Amotor for electric tele* graphs or signals, but it will be understood that the invention is not limited te such pari ticular use, being adapted for service in other connections where it is desired to provide a step-by-step operation through a comparatively large number of positions by the use of a minimum of field magnets and at the same time provide for accurate positioning of the rotating element. in either ot X the steps or positions.I

In apparatus designed for Vsignalling purposes, as for -instance shipswtelegraphait. has beenthe practice tolocate a dial or \pointer on the shaft or other partY of a roto deliver the predetermined signal.

. tatingelement, the 'step-by-step movements of the latter beingy arranged to shift the position of the indicator in such manner as common form of such apparatus is designed to locate. the indicatorc in either one of ten positions through the action of groups of magnetsarranged in parallel to co-oper-V ate`with two polarized elements carried by the rotating element, the grouping being Vvchangcdto provide the element movements. One form of such apparatus-shown, for

instance, in the prior patent granted to ine June/23, 1914, o. 1,100,860-employs live sets or pairs of iield magnets, the pairs being `axially alined and connected inseries with each magnet vhaving a pcie vpiece adapted to co-operate with a polarized element; by means of a suitable circuit make and break device for the circuits of the lfield magnets various groups orr1 Lthe field magnet circuits can be completed, thus energizing the pole pieces of predetermined ART O PRDUCING STEP-SBY-TEP i MVEMENTS.

l specification of teaersrten-a Pawnee@ Mm, 7, 1922, vApplication lec. November i3, 193,6, Serial No. @$2,313.

Viiield magnets to provide that co-'operation with the polarized element necessary to produce the step-by-step operation.

rll`he present invention is designed to increase the total number of step positions in which it is possible to accurately position the rotating element without the necessity of increasing correspondingly the number of field magnets or polarized elements, this result being obtained by changing the general character lof the. groupings of the magnetrircuits, and by providing a cha-nge in the polar configuration of the polarized ele ments, it being understood of course that the circuit make and break device will 'be changed to meet the changed conditions. F or instance, instead of obtaining only the ten position operation by the use ot the tive sets or airs of magnets disclosed in' the patent referred to, the number of such positions can be increased tol twenty, doubling the number heretofore obtained, the movements of the-rotating element to each position being with certainty and providing van accurate' location of the element in such position. bviously, the principles of the invention may be applied to structures employing a greater or less number of such sets or pairs of magnets; for instance, motors Vhaving three, nine or ifteen ot such sets or pairs may be .operated infiaccordance with `these general principles, these :of salient poles, each element having more than two 'of such poles equally spaced-the particular form shown herein utilizing tour salient poles since the particular embodiment is ,designed to double the number of step positions heretofore obtained. Another characteristic is ,that of producing the step by-step movements through varying the number of active magnetic circuits, a minimum number being employed in advancing an element to and maintaining it in one oiu the step positions, the succeeding advance being provided by establishing an additional magnetic circuit. effective on the polarized structure, this additional circuit being maintained in addition to those previously established in maintaining the rotating element in its advance position; the succeeding advancemovement ofthe rotating element is produced by rendering one ofthe firstestablished circuits inactive, thus again re, ducing the number of active magnetic circuits lto the former minimum number, the structural difference being, however, that during 4the advance of the two vsteps one field was thereby rendered inactiveand an- 10y other added to take its place. By the combined action of these characteristics, the number of steps possible ina complete revo- Alution of `the rotating elementv is not only doubled but each-step is provided positively and with accuracy, thedefnite polar area of the salient pole formation producingthe f effect of a magnetic lockwhich ensures that the movements will be-of definite length 'and free from the over-runningv orunder-running or other oscillatory effects'.

To these and other ends, therefore, the. nature of which will.. be readily understood as the invention is hereinafter'. disclosed, said invention consists in the methods and apparatus for exemplifying the. same hereinafter more fully disclosed,'illustrated in the'accompanying drawings, and more particularly pointed out inthe appended claims.

In the accompanying. drawings similar reference characters indicate similar parts in each of the views,- f

ing magnetic'circuits.

` onefspecific embodiment on y ,of apparatus employed by mein carrying out the prin-4 ciples of the invention,l it will be understood that this structure is illustrativeonly both as to structure and number of field magnets employed, the invention not/'being limitedV l in these respects. 1For explanato y purposes "a brief description ofthe speci c- Vform 1s given.'

15 indicates an insulating base on which the structure is mounted, this base carrymg suitable contacts 16, lcorresponding in num-n 'ber and .properly arranged to provide electrical connection with the several field magnets indicated respectively at 17, 18, 19,'20 and 21.1 In the embodiment shown, themagnet structure is' designed. to be removable bodily from the base and hence theI particular form of connection between a magnet ,jin which the 'sa-me taken yon line 2--2 of Fig. 1.'

and its contact 16 is automatically enga e; able, this being provided) by contact 22v or each magnet, contacts 16 and 22 having contact engagement when the parts are assembled.

These magnets are Amounted on' and insulated from 'a plate 23, this plate carrying the several magnet cores to the` other ends necting the cores of the second group at the opposite end )of the magnets. Each pair of alined magnetsfor instance 17 and 17a-are connected in seriesl and wound in the same direction, thus producing polarities of opposite sign in the respectlve pole pieces24 and 24". Each pair of field magnets is also electricallyconnected to one of the segments of a circuit make and break device,l as shown more particularlyin Fig. 8, the leads extending tothe first group of'magnets; and as shown in said figurefthe second group of magnets are individually connected to a common terminal shown diagrammatically as in the form of a ring conductor 40 to which the magnet terminals aresecured.

The several pairs of field magnets are shown as yarranged symmetrically about a shaft 30 in a` concentric relation to such shaft with the magnet pole pieces extending in radialdirections relativethereto. This provides for equal spacing of the magnets and equal distances between adjacent :Shaft 30 1s shown as'mounte in plates 23and; -29 and forms the axis of an independent pair of alinedmagnets 31 and 31a secured respectivelyto said plates 23 and 29 and held against rotation. The cores of magnets 31 and 31a are secured to the shaft and are rotatable relative to the magnets, said cores each carrying a. pole piece, theseJ being indlcated at 32 and 32a. `Magnets 31 and 3l are connected inlseries and w the same direction as in the pair of field vThe outer end of'` the shaftis shownas carrying anindicator 33 of suitable type, the

.purpose of theapparatus shown being toprovide'step-by-step movements. to the latter."

A s shown 'in-Fig.` 1, each of pole pieces 1 30 unsy (pole pieces.

i 32and 32a have their polar faces in the form of salient poles, these being shown as four in number and indicated respectively as a,. b, c and d for pole pieces 32, and ai, b', c and al for pole piece 32a. rlPhese poles are uniformly spaced and may be of vequal polar greater than two in each of the pole pieces.

The manner of Wiring the* apparatus shown and describedis illustrated diagrammatically in Fig. 8, 34 indicating a circuit' make and break device one element of which is" shovvnas a pair of brushes 35-and 3 5 movable in vunison Vand respectively connected to opposite sides of a source of elec,- trical supply, the other element' being shown as a member 36 carrying a' plurality of segments, shown' as five in numberkk and indicated at fm, 4t, 0 p and g,^the number'lcorresponding to the number of pairs of field magnets shown, these segments being insulated from eachother. As 'will be understood the number of segments Will :vary as the character of the apparatus is changed, the number generally corresponding-to vthe number of pairs of field magnets being utilized.

The segments areconnected to the respective field magnets of the first group, the par- -ticular arrangement disclosed showing the following connections by suitable leads: m with 17, n With 18, o with. 19, p with 20 and givith2l. g i

F ig. 8 represents the position of the circuit make and break elements when the apparatus is in Jthe position shown in Fig. 1. The electric circuits closed in this position are from line A to brush 35, segment m magnet4 17, magnet 17a, conductor -40 and return t'o brush 35a in the form of parallel circuits from conductor 40 through magnet 19a, mag"- net 19 and segment 0, and through magnet 20a, magnet 20 and segment p, brush 35n bridging segments o` and p and being coni nected to line B. As will beunderstood this has the 'effect l of energizing three of the five -pairs of field magnets, one magnet of each pair, however,

.being inactive in the production of a magnetic circuit affecting the rotating element by reason of the fact that pole pieces 32 and 322L extend radially' in opposite directions. Hence, the completion of the circuits just describedA serves to produce three effective magnetic circuits, one 'through 4the core of magnet l, pole piece 24u, pole piece 32a,core of magnet 31% to plate 29,

,the other two magnetic "circuits being -in condition Wil ningthrough the core of'magnet 20 and its pole piece27 to lpole piece 32fand then as before. A A Owing to the lncationA of the several statlonary pole pieces' and the salient pole formationpof pole pieces32 and,32a, yit WillK Jbeing' opposite pole piece 26 and two opposite piece 27. This provides a balanced relation in the fields thus produced. and magnetically locks the rotating element in this position. Y

lf, at this time,lbrushes 35 and '35l be' shifted so as to cause brush 35'to also contact with segment a--b-rush 35LL stillv bridging segments o and p-an additional electric cir-- cuit is Jcompleted running from line A through brush 35, segment n magnet 18, andr magnet 1'8afto ring 40 and return through either or both of the `return circuits previously described -tobrush 35a and line B.

rlhe completion .ofthis additional electric.

circuit energizes field magnets 18 and 18a,

and sin/ce pole piece 25l is located; proximity to pole piece 32a, the previous balanced be disturbed by the magnetic influence of pole piece 25, with the result that pole piece v32?a will be drawn clockwise in Fig. lvuntil salient pole d is brought opposite pole piece 25a and completes an additional magnetic circuit through the` core roo of magnet 18a, pole piece 25?, pole piece '32a 'I (salient pole d) the' core of magnet 31a and plate 29. .'lhis movement of pole piece 32a causes a vcorresponding movement of both polarized elements with the result that the shifting action changes theY relative arrangement of salient poles to the pole pieces, two

of the field magnet pole pieces-24al and 28m facing three salient poles, While magnet pole pieces 25Pand27 eachI face one salient pole, completing four effective magnetic circuits instead ofthe three utilized in the previous position, an increase of onemagnetic circuit to the previously established magnetic circuits.

ile Since the polar areas ofthe salient poles are definite, the movement into the new,

" through magnets 17and 18 having a common return through magnets 2()a and 20 and thereby restoring the operating conditions of three magnetic cincuits with the difference that the parallel return condition of Fig. 1 is substitutedy by the single return of Fig. 4,

the parallel relation" being transferred from A,

the negative to the Ipositive side of the structure. In the new position the salient poles of pole piece .32a are equally divided between pole pieces 24a andl 25a, while the salient y poles of pole piece 32 are common to pole piece 27. 1

In the advance of the rotating element to the succeeding position or step (Fig. 5), the four, magnetic' circuit condition is again -produced by rendering magnet 21a active through shifting of brushes 35 vand 35a to the-succeeding position, brush 352L taking its 'irst position on segment g so that it bridges segments p and g. Establishing this additional electric circuit renders pole piece 28a active to affect the previous position of the y polarized elementsthe `latteradvancing to Abring salient pole a to its position relative to pole piece 28,the change'leaving salient pole a active with pole piece 24, the remaining three salient polesof each polarized element being active respectively with pole pieces 25 and 27a.

The succeeding position or step is produced by again reducingk the number of electric circuits'through shifting ofbrushes 35 and '35, the circuit through magnet 17l being broken, leaving the circuits of magnetsl 18,

' 20xL` and 21"aL completed, again establishing the condition of three magnetic circuitsl through 45 movement of the polarized elements toward .the condition of balance (Fig. 6) all of the salient poles of element 32 operating witliA pole piece 25', the salient poles of element pieces 27a and '28,

Comparison of Figs. l and 6 will show that the saine general. electrical and' magnetic conditions exist in the two positions, the difference being that the single magnetic circuit on the positive side has been changed from magnet 17 tomagnet 18, and that magnet \21.has beensubstituted for magnet 19a onthe negative side, advancing the rotating velement an angular distance of 7 2. In reachingthis position,I the, rotating element i 328k being equally divided between pole haspassed through-'three intermediate positions or steps in each `of which the magneti- A cally-locked conditions were present so that the rotatingkelement could. be'positively and V- accurately maintained in each of such posiy one in the number of magnetic circuits, this f cycle can be repeated until the polarized elements also have made a complete revolution, carrying the rotating element through a succession of twenty positions or steps.

From the-above it will be clear-that at no time is there activity concurrently of all` of the pairs of field magnets, the activity being of the succession of three and four of such pairs, but in traversing the entire revolution, all of the pairs will have been active at various times. For instance, when the advancing movements of the rotating element have reached the position shown in Fig. 5 (Fig. 1 being assumed to represent the firstv step), each of the five pairs of magnets will have been made active; While this is a characteristic of the five or more pole structures, the three-pole structure does not havey this characteristic, since in each alternate position all of the pairs will be active.

It is apparent that by suitably energizing selected magnets in the method disclosed the shaft and indicator carried thereby may be made to assume 20 different positions. -In a complete cycle of operation, which includes a complete step-by-step rotation of the shaft inthe manner described, it will be apparent that each pair of magnets will be active for seven successive steps, then inactive for three steps, and then again active for the succeedlin seven steps, the latter period of activity -from minimum to maximum and then return to minimum, each of the poles, however, 11i

being active in each position,l any change from the maximum with a pole piece placing the remaining poles in operative relation to an adjacent pole piece with which the change in number is reverse to that taking place withv respect to the first pole piece.

While I' have herein shown and described one way in which the principles of the present invention may be utilized, it will be readily understood that the disclosure is more or less illustrative, it being obvious that changes or modiicationstherein may be required or found desirable in meeting the I various exigencies of use. I desire to be understood, therefore, as reserving the right 55, windings ,with the windings energized at to make any and all such changes or modications as may be found essential or desirable insofar as the same may fall within the spirit and broad scope of the invention as expressed in the accompanying claims.

And while l have herein' referred to the apparatus asof the step-by-step type, having all of the advantageous characteristics( of that type, it is to be understood, of course, that the particular construction shown hasY the additional advantage of direct reading, in that the particular arrangement will per, mit the indicator to pass direct to the proper point without step-by-step action. That is, the position of the magnet at any time is positive and deinite, being independent of its previous position; so that, should the current be interrupted and the rotating element displaced, the restoration ol the current will return the indicator to a correct positiont, as indicated by the particular position o msm.

Having thus described my invention, what the circuit make and break mecha- ;ll claim as new is:

l. ln an electric indicator having `*a rotor comprising a plurality of polarized elements and a stator comprising a series ol at least four magnetic windings having'pole pieces cooperating magnetically with said polarized elements and So arranged that the action of less than the total number ci windings will hold the polarized elements in a predetermined position, the method of shifting the polarized elements which consists in varying in successive steps the number of windings energized so as to produce more thanv two positionings of a polarized element between stator windings and in energizing at each step a series of at least, three windings and less than the whole series of windings with the windings energized at each step `taking in more than two right angles about" therotor whereby a substantially balanced and interlocking relation is provided at each step between the stator and the rotor.

'2. ln an electric indicator of the t pe recited in claim l, the method of shitting the polarized elements which consists in first increasing and then decreasing the number ot windings energized so as to produce more than two positionings of a polarized element between adjacent stator windings and in energizing at each step a seriesvoi at leastthree windings and less than the whole series oit 8. 'lnm apparatus'lfor providing step by step movement of a rotr by the resultant 4action of a -plurality of magnetic circuits, a stator comprising a plurality of spaced field magnets veach provided with a pole piece, a rotor cooperating. therewith and including a plurality oit polarized elements, the polarized elementseach being providedl with more than two equally spaced salient poles for cooperation with the tield magnet pole pieces whereby the polarized elements are adapted to assume more than two positions between adjacent iield pole pieces in the production ot the magnetic circuits, with all the salient poles active at each position oi the same.

e. ln an apparatus for providing step by step movement ol" a rotor bythe resultant action or" a plurality of magnetic circuits, a stator comprising a plurality of spaced iield magnets provided with pole pieces, a rotor cooperating therewith and including a pair ol oppositely positioned polarized elements,

the polarized elements each being provided with more than two equally spaced salient poles tor cooperation with the field magnet pole piece, the construction being such that the polarized elements are adapted to assume more` than two positions between centers ol adjacent field pole p ieces in the production ot the magnetic circuits, with all the salient poles active at each position of the same,

5. ln an electric motor, a stator compris-b ing a plurality ol spaced field magnets provided withpole pieces and a rotor including a plurality ot pole pieces, each rotor pole piece being provided with more than twov equally spaced salient poles, the length'of each stator pole piece tace' being equal to the distance between the 'opposite sdes'of pole piece laces being equal to the distance between adjacent sides of two salient poles ot a rotor pole piece.

6. ln an electric motor, a stator comprising a plurality of spaced field magnets proetv the end salient poles of a rotor pole piece and the distance between adjacent stator" vided with pole pieces and a rotor including pole piece, the distance between adjacent salient poles being equal to one-fourth of the distance between the centers of adjacent stator pole piece laces.

'7. ln apparatus for providing step by step movement ol a rotatable element by the 1 resultant action ot a plurality of magnetic circuits, a pair oit polarized elements movable in synchronism with the rotatable element, and a plurality of iield magnets having p'ole pieces operative with said polarized v lelements to position the latter in more than j l two positionings between'adjacent eld magnet pole pieces inthe select-ive production of the magnetic circuits, said polarized elements e'ach having more than two equally l spaced salient poles all active in the completion of the circuits at each positioning of the I. said polarized elements'. i

. 8. Int apparatus -for providing step by Step movement of a rotatable element by the resultant 'action of a plurality of magnetic,

circuits, a pair of.polarized elementsfmovable in synchronism with the rotatable elecarrying a single pair of armatures, each Y ment, and a plurality of `field magnets having pole pieces operative with said polarized elements to cause the latter to assume more than two positions between yadjacent `fieldmagnet pole pieces in the selective produc- .tion of the magnetic circuits, said polarized elements having an equal number of equally spaced salient poles all active in 'the completion of the circuits at each position of the polarized elements, the number ofsalient polesfof a polarized element being greater than two.

9. In apparatus` for providing step by step movement of a rotatable element by the resultant action of aI plurality of magnetic circuits, a pair of polarizedl elements movable in synchronism with the rotatable element, and a plurality of ield magnets having pole pieces operative withsaidpolarized elements to establish four positions of the latter from eld pole to field pole in `the selective production of the magnetic circuits, said polarized elements each havingA four salient poles all active in the completion of the circuits at each position of thev polarized elements. J

v10. An electric indicator having a rotor provided with a plurality of salient poles, stator `comprising a plurality of magnet windings spaced about the rotor, each winding having a pole piece cooperating with said armatures, and means for energizing said windings `including provisions for varying in successive steps the number of windings energized so as to produce. more than two positionings .of an armature lbetween adjacent stator windings, such provisions being adapted for energizing more T than two windings at each step.

1l. An electric indicator having a rotor carrying a plurality of armatures, a stator comprising aI plurality of magnet windings spaced about the rotor, each winding having a pole piece cooperating with said armature, and means for energizing said windings, including provisions for vatryin in successive steps the number of windings energized so as to#4 produce more than two positionin-gs of aniv amature between adjacent stator windings, such provisions being adapted forenergizingl at each step a seriesof three or more windin less than the total number of stator vwindings and` spaced about the rotor for more than two right angles. I

12. An electric indicatorhaving a rotork carrying a single pair pf armatures, each j provided with a plurality of salient poles,

a stator comprising a plurality kof magnet windings spaced vabout the rotor, each winding having a' pole piece cooperating with said armature and means for energizing said windings including provisions. for -first energizing more `than two "windings and then energizing more than three windings spaced about the stator s'o as to produce more than two 'positionings of an armature between adjacent stator windings. j

13. An electricindicator having a rotor, field Nmagnets concentrically located, about said rotor, armatures on said rotor cooperating with pole pieces on said magnets, each of lsaid armaturesfhaving more than two equally spaced salient poles', the length ofeach pole piece face being equal to the distanc'e between the oppositesides of the-end salient poles, and the distance between adj acent` pole piece faces'being equal to the distance between adjacent sides of two salient poles. Y

1 4. An electric, indicator; having a rotor,

field *magnets concentrically located, about` 'said rotor," armatures on said rotor cooperat- .ling with pole pieceson said magnets, each of said armatures having more than two equally spaced salient poles, the length of eaclr pole piece ace being equal to the ldistance between the opposite sides of the end salient iool poles and the distance between adjacent pole piece faces vbeing equal to. the distance Jbetween adjacent sides'of two salient poles, the -distance between adjacent salient poles being equal to a quarter of the distance between the centers of adjacent pole piece faces.

15. In apparatus for providing step-by- 'step movement toa rotatable element by the resultant action of a plurality/of magnetic circuits, a pair of polarized elements movableinsynchronized relationlwith the rotatable element, a plurality of field magnets having pole pieces operative with said polar- Y ized elements to yestablish magnetic circuits, j

said polarized element-s. each having four salient poles all active in the completion of -the pole pieces of adjacent magnets operative with a polarized. element being spaced a disl tance to locate adjacent salient poles of the polarized element in operative relation to the respective pole pieces when the polarized velement is operative with both pieces, and

means whereby advancing movements of the rotating element through a succession of steps will progressively change the number of salient poles active with a pole piece.

17; In apparatus forproviding step-bystep movement to a rotatable element by the resultant action of a plurality of magnetic circuits, a pair of polarized/elements movable in synchronism with the rotatable element, Ia plurality of` field magnets having pole pieces operative with said polarized element-sto establish magnetic circuits, said polarized elements each having four salient poles active in the completion of the circuits,

the pole pieces of adjacent magnets operative with 'a polarizedfelement being spaced a distance to locate adjacent salient poles of the element in operative relation to the respective pole pieces when the element is operat-ive with bot-h pieces, and means whereby advancing;l movements ofthe rota-ting element-through a succession of steps will progressively change the number of salient poles active with a pole piece with the progressiverelation of one pole piece the reverse of that of the other pole piece. 18. In apparatus for providing step-bystep movement to a rotatable v,element by theresultant action of a plurality of magnetic circuits, a pair of polarized elements movable in synchronsim with the rotatable element, a plurality of field magnets having pole pieces operative with said polarized elements to establish magnetic circuits, said polarized elements each having four salient poles active in the completion of the circuits, and means whereby the number of salient poles of apolarized element active with a predetermined pole piece will be equal in number to the lnumber of poles active with an adjacent pole piece in one position of the rotating element and be of unequal number relation thereto in a succeeding posit-ion of such rot-ating element.

In testimony whereof II have hereunto set my hand.

FRANKW. Woon. y 

